A post-metallocene titanium(IV) complex bearing asymmetric tetradentate [ONNO]-type amino acid-based ligand and its activity toward polymerization of polar monomers at room temperature in aqueous emulsion

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• 作者：K. Sharma ; Sudip K. De
• 关键词：Early transition metal ; Post ; metallocene catalyst ; Aqueous polymerization ; Viscosity average molecular weight ; Polymethyl methacrylate ; Polymethyl acrylate
• 刊名：Colloid and Polymer Science
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：294
• 期：12
• 页码：2051-2070
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Polymer Sciences; Soft and Granular Matter, Complex Fluids and Microfluidics; Characterization and Evaluation of Materials; Physical Chemistry; Food Science; Nanotechnology and Microengineering;
• 出版者：Springer Berlin Heidelberg
• ISSN：1435-1536
• 卷排序：294

文摘

Due to increasing environmental concern regarding detrimental effects of organic solvents, a new post-metallocene titanium-based catalyst [TiLCl₂] {LH₂=2-(3,5-Di-tert-butyl-2-hydroxy-benzylamino)-succinamic acid} with sidearm approach has been synthesized for aqueous emulsion polymerization of olefins. The catalyst has been characterized by elemental analysis, 1H NMR, 13C NMR, HRMS, IR, and UV–visible spectroscopy. The catalyst is easy to synthesize and is moderately stable in water. In aqueous emulsion, in the presence of co-catalyst NaBPh₄, it has been found to exhibit moderate to high activity in the range of 104 to produce homopolymers and copolymers of methyl acrylate and methyl methacrylate which are widely used for a variety of applications. The influence of the main reaction parameters on the polymerization reactions at room temperature was studied including the catalyst/co-catalyst ratio, type of monomers, reaction time, etc. Structures and properties of the obtained polymers were analyzed by various instrumental techniques like differential scanning calorimetry (DSC), gel permeation chromatography (GPC), 1H NMR, 13C NMR, etc., as well as by various experimental methods. The results indicated that the PMMA and PMA produced by the newly synthesized catalytic system are syndiotactic rich and possess ultrahigh-viscosity average molecular weight in the order of 106 g/mol.